This invention relates to a stamping apparatus in general, and more particularly to an apparatus for stamping indicia on moving workpieces.
There are many applications in which it is important to stamp indicia on a workpiece, including workpieces which move in a path. One of the most problematical of these applications is the stamping of indicia on workpieces in rolling mills for steel and other metallic materials, where it is necessary to clearly indicate on each workpiece the particular type or quality of material. Heretofore, this has been accomplished by manually stamping the indicia upon the moving workpiece, e.g. a billet, strip or the like. However, aside from the fact that this is a rather labor-intensive procedure it is also quite dangerous for the workers involved because the workpieces are in movement and often are extremely hot. The apparently simplest solution to the problem, namely merely to replace manual stamping with mechanical stamping, is not readily possible because the ink used for the stamping purposes dries very quickly on the stamp (especially in view of the hot environment) and because the stamp itself tends to become soiled quite rapidly. One solution that has been proposed to the problem is the use of rollers which roll on the surface of the workpiece and are provided with the stamps; however, this has the disadvantage that it is not possible to change the indicia without at the same time also changing the rollers, because each roller incorporates only one specific stamp. Also, another disadvantage of this proposal is that it does not make it possible to affix the stamp with adequate position on a particular part of the workpiece. This is important because when profiled workpieces travel in a path in a rolling mill it is often necessary to change the indicia to be stamped onto them as when the profile changes, sometimes from workpiece to workpiece. Evidently, it is not possible to stop the rolling mill to exchange one roller for another having a different stamp.
Such rapid changes in the indicia to be stamped onto the workpieces are also necessary if for example one of the workpieces is found to contain some sort of flaw, because such a flaw must be immediately apparent from the indicia stamped onto the workpiece to assure that the workpiece is subsequently used only for certain applications for which they still fit in view of the detected flaw.